Typically, the assembly of an electronics module involves mounting various electrical components to a printed circuit board. Electrical components, such as transistors, generate significant amounts of heat requiring special provisions to dissipate the generated heat. The electrical component should be in thermally conductive contact with a heat sink to obtain maximum heat transfer from the electrical component to the heat sink. This conductive heat transfer is directly proportional to the contact pressure between the component and the heat sink.
Various spring devices have been designed for urging an electrical component into contact with a heat sink. U.S. Pat. Nos. 5,225,965 and 5,170,324 illustrate a spring clip for urging an electrical component into a heat conductive relationship with a vertical heat sink. These spring clips exhibit a common deficiency: they are retained in position by clamping over the top of the vertical heat sink. This configuration prevents the use of a heat sink as an outside wall of a sealed electronics module. Furthermore, due to the method of retention, the effective spring force applied to the electrical component is dependent upon the tolerances of the retaining clamp.
For a compact electronics module it would be desirable to provide a spring clip for urging an electrical component against a heat sink which also serves as an exterior housing for a sealed electronics module. Still further, it would be desirable to provide a spring clip that is capable of exerting a force on the electrical component independent of precision tolerancing, thereby eliminating high costs of precision tolerancing.